AT&T reinvent the wheel (via New Scientist). “a user could safely sign up for a monthly email newsletter by specifying the source of the newsletter and limiting it to 12 messages over the next year. If the address fell into the hands of spammers, their messages would be blocked by the software before it reached the user’s inbox. ‘The ‘Single Purpose’ address system reduces spam by stopping it right before the user sees it,’ says John Ioannidis, at AT&T’s research laboratory in New Jersey, US. The software is currently at the prototype stage.”
In other words, they’ve re-written TMDA, The Tagged Message Delivery Agent. Nice one.